Gjemnessund Bridge
Encyclopedia
The Gjemnessund Bridge is a suspension bridge
that crosses the Gjemnessundet strait
between the mainland and the island of Bergsøya
in the municipality of Gjemnes
in Møre og Romsdal
county, Norway
. The 1257 metres (4,124 ft) long bridge is the longest suspension bridge in Norway, although it does not have the longest span (623 metres (2,044 ft)). Gjemnessund Bridge was opened in 1992, and has 21 spans with a maximum clearance to the sea of 43 metres (141.1 ft). It was built as part of the Krifast
project, the mainland road connection of the city of Kristiansund
(along with the Freifjord Tunnel
and the Bergsøysund Bridge
).
Many bridges slowly deteriorate and need to be repaired because the salty seawater
damages the concrete
and the iron inside it. The Gjemnessund Bridge has had a problem with seabird
s, whose manure
contain salt and ammonia
. The salt and ammonia damages the concrete. To prevent this, the bridge is cleaned, and the critical parts of the concrete are covered with an elastic
membrane that protects the concrete against the manure and the harmful content.
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...
that crosses the Gjemnessundet strait
Strait
A strait or straits is a narrow, typically navigable channel of water that connects two larger, navigable bodies of water. It most commonly refers to a channel of water that lies between two land masses, but it may also refer to a navigable channel through a body of water that is otherwise not...
between the mainland and the island of Bergsøya
Bergsøya
Bergsøya is an island in the municipality of Gjemnes in Møre og Romsdal county, Norway. The island is located near the junctions of the Freifjorden, Kvernesfjord, and Tingvollfjorden. The highest point on the island is the tall mountain Varden....
in the municipality of Gjemnes
Gjemnes
Gjemnes is a municipality in Møre og Romsdal county, Norway on the Romsdal peninsula. It is part of the Nordmøre region. The administrative centre is Batnfjordsøra, which lies along the Batnfjorden and is a former steamship landing place...
in Møre og Romsdal
Møre og Romsdal
is a county in the northernmost part of Western Norway. It borders the counties of Sør-Trøndelag, Oppland and Sogn og Fjordane. The county administration is located in Molde, while Ålesund is the largest city.-The name:...
county, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. The 1257 metres (4,124 ft) long bridge is the longest suspension bridge in Norway, although it does not have the longest span (623 metres (2,044 ft)). Gjemnessund Bridge was opened in 1992, and has 21 spans with a maximum clearance to the sea of 43 metres (141.1 ft). It was built as part of the Krifast
Krifast
The Kristiansund Mainland Connection is a road system on the highways and that connects the municipality of Kristiansund to the islands of Frei, Bergsøya, and Aspøya to mainland Norway. Krifast opened in 1992 and consists of of road and of bicycle paths...
project, the mainland road connection of the city of Kristiansund
Kristiansund
Kristiansund is a city and municipality on the western coast of Norway, in the Nordmøre district of Møre og Romsdal county. It was officially awarded township status in 1742, and it is still the major town for the region. The administrative center of the municipality is the city of Kristiansund...
(along with the Freifjord Tunnel
Freifjord Tunnel
The Freifjord Tunnel is a long undersea tunnel under the Freifjorden in Møre og Romsdal county, Norway. The tunnel begins on the island of Frei in the municipality of Kristiansund and then descends below the Freifjorden and ends on the island of Bergsøya in the municipality of Gjemnes...
and the Bergsøysund Bridge
Bergsøysund Bridge
Bergsøysund Bridge is a pontoon bridge that crosses the Bergsøysundet strait between the islands of Aspøya and Bergsøya in Møre og Romsdal county, Norway. The bridge is long, the longest span is , and the maximum clearance to the sea is . The bridge has 13 spans.Bergsøysund Bridge was opened in...
).
Many bridges slowly deteriorate and need to be repaired because the salty seawater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...
damages the concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
and the iron inside it. The Gjemnessund Bridge has had a problem with seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s, whose manure
Manure
Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...
contain salt and ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
. The salt and ammonia damages the concrete. To prevent this, the bridge is cleaned, and the critical parts of the concrete are covered with an elastic
Elasticity (physics)
In physics, elasticity is the physical property of a material that returns to its original shape after the stress that made it deform or distort is removed. The relative amount of deformation is called the strain....
membrane that protects the concrete against the manure and the harmful content.